question about Philips System One: Remstar Auto A-Flex

[SnoringGuy]

When importing and viewing a report using Sleepyhead, how acurate are the reports? I mean how acurate is the information that my Philips System One machine is producing? I find it amazing how much info this little device records. When I had my sleep study, I was hooked up with two dozen probes. I had them in my hair and all over my body. It took me two days to get that goop out of my hair.

Question. How much HDD space does the data consume when I import this data into SleepyHead every day? It does give an option to compress the data when imported. I only have a 120GIG SSD in my used laptop. Is this going to consume all my free space? Or should I start looking for a bigger capacity drive? Or can I save this data to another location?

[archangle]

You probably won't go over a gigabyte or two for a PRS1 machine.

Do you have a hard disk in the machine as well? You can move the data directories.

[archangle]

Re: Accuracy

I suspect that for the things it actually measures directly, it's pretty accurate. Certainly accurate enough to treat apnea. On an auto machine, it adjusts to keep the apneas down. The apnea detection is based on changes in airflow, so accuracy of the raw data is less critical.

A CPAP machine can't tell whether you're asleep or not. You shouldn't count AHI when you're awake, so there's an "inaccuracy" there.

Distinguishing central from obstructive apneas really requires a chest effort belt, but the PRS1 and S9 machines do a pretty good job figuring it out from the airflow and pressure and some tricks.

Air leaks can screw up some of the data.

The CPAP machine can only measure pressure at the machine, not at the mask, but they probably do a pretty good job of estimating the pressure at the mask.

Detecting a hypopnea "correctly" requires an O2 sensor and an EEG, so the machine scored hypopneas are not as "accurate" as an in polysomnography (PSG) lab study. It's still useful information, but you need to realize that the definition of "hypopnea" is different, and the CPAP may record a hypopnea where the PSG doesn't, and where the "hypopnea" may not actually have any harmful effect on your body.

Even a trained medical tech with full PSG data will not always score the same reading on what is and isn't an apnea. I think this is mostly a problem when the apnea is "borderline" in terms of being long enough or severe enough to count. I think all the CPAP machines will correctly score the important and severe apneas. i.e. If you have severe apnea, the machine will score it "correctly." If you're in the gray area, the readings are debatable, even with a human reading the data.

This is one of the reasons it's good to have a fully data capable machine and to look at the waveforms involved with a program like SleepyHead.

[SnoringGuy]

You probably won't go over a gigabyte or two for a PRS1 machine.

Do you have a hard disk in the machine as well? You can move the data directories.

Are you saying that each time I import data from my sd card, that data is one gigabyte in size?

[CapnLoki]

Are you saying that each time I import data from my sd card, that data is one gigabyte in size?

I have the same machine as you; 150 days of Sleepyhead data are only 82 megabytes, so its under 200 mB a year. Hard to believe you can record every sleeping breath you take for the rest of your life on a chip smaller than a fingernail!

[woodworkerjunkie]

I just checked my folder and having 723 days of data (almost 2 years) the file is only 60.5 MB. My SD card is 4 gig and it shows 5% used. The file on my hard drive is the exact same as on my SD card, 60.5MB in size.

[palerider]

You probably won't go over a gigabyte or two for a PRS1 machine.

Do you have a hard disk in the machine as well? You can move the data directories.

Are you saying that each time I import data from my sd card, that data is one gigabyte in size?

just look on the sd card and see what files are dated for last night, and see how big they are.

[archangle]

You probably won't go over a gigabyte or two for a PRS1 machine.

Do you have a hard disk in the machine as well? You can move the data directories.

Are you saying that each time I import data from my sd card, that data is one gigabyte in size?

No. If you use SleepyHead for PRS1 data for a year or so, you'll probably have less than a Gigabyte of data on the PC.